At the time I did the drawing, I found the outline to be a little on the thin side. The outlines of the existing flemoids are much thicker, as can be seen in the screen shot.

When retracing an object for animation, the outline is usually drawn with a brush and ink. The reason for this is because of the control allowed by the brush to vary the thickness of the line being drawn. The varying degrees of thickness simulate a slight 3D effect. If you look at drawings in classic animation, you will notice that most curved lines are thickest in the middle and taper down to points at the ends, to make the curves look more pronounced, objects tend to have thicker lines at the bottom, to give then weight, and the exterior outlines of objects tend to be thicker than the lines used on interior details, to make them stand out from the background. All of this makes drawings appear more dynamic, and that is why brushes are used for inking drawings in comic books and animation.

The problem is I really suck at using a brush.

The outlines of the flem pod were done using a coloured pencil. I am able to vary the thickness of my lines with a black coloured pencil by changing the pressure I apply to the pencil. I use a black coloured pencil rather than a graphite pencil, because the lead does not crush the way the lead of a graphite pencil does. It is much more forgiving, so my results are pretty good.

The problem is the lines drawn with a coloured pencil are thinner than the ones that can be drawn with a brush, meaning I can not make them match the lines thicknesses of the existing flemoids. Also, I can not scale the new thinner lined objects to the same scale as the originals. I tried it with the flem pod. The lines became almost invisible when scaled down that far. It looked terrible, and I was forced to do it at a higher resolution.

After so much talk, I have one question.

Should I try to make my sprites with a thicker outline to try making them match the originals, or should I stick with the thinner outlines, which are much easier for me to do?

I kinda like 75's edit. So that's my opinion, Boingo, that you should go with slightly thicker lines - it mimics Chex Quest's cartoony style that is so important if you ask me. However, your style is also very important - and perhaps these thinner lines is simply your style. Unless you don't like them. All in all, go for your style whatever that is unless you want more to emulate Chex Quest's designs.